This invention pertains to pails or other open-top vessels of various shapes and sizes which contain solutions or mechanical mixtures which are required to be blended. This is a very common need in a wide range of industries which process food products, pharmaceutical products, inks, paints, coatings and general chemical products of many types. There exists a need for a powered mixer which can safely, efficiently and cleanly mix the contents of open-top vessels.
The industry widely relies on an open-impeller type mixer design. This typically comprises a rigidly mounted motor with a spinning shaft and impeller arrangement. This existing technology fails to meet the full performance of the present invention for any or all of the following reasons: Open impeller mixers are unsafe due to the fact that they put the operator in close proximity to exposed, moving mechanical parts, which poses risks of entanglement, cutting or other serious injury or death. Open impeller mixers often align the axis of the impeller assembly at the centerline axis of the vessel, which induces a single, pronounced vortex with sufficient amplitude to allow atmospheric air to reach the impeller and cause aeration of the product being mixed. Open impeller mixers typically require cumbersome manual adjustment at the beginning and end of each batch to raise, lower and otherwise adjust the impeller assembly relative to the vessel. Once the vessel being mixed is removed, open impeller mixers have no provision to prevent residue from dripping from the impeller and shaft. Open impeller mixers typically require the end user to install several separate systems to accommodate the structural support of the mixer and the vessel, to power and control the mixer, to raise and lower the mixer in and out of the vessel, and to evacuate hazardous dusts and vapors created during mixing.